Siemens SIMATIC S7-1500T - Page 40

8 Example Application
8.3 Programming of the processing stations
TOs of S7-1500(T)
Entry ID: 109743134, V1.0, 05/2017
40
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 Positioning axis technology object – master axis of the curve synchronization:
Determination of the modulo settings of the technology object, in order to be
able to correctly calculate the position for the start of the synchronism in
relation to the position of the conveyor belt.
//+++ Get technology objects data +++
//Check interpolation of cam disc
#tempCamDiscStatusWord := #CamDisc.StatusWord;
#statCamIsInterpolated := #tempCamDiscStatusWord.%X5;
//Get modulo settings of master axis
#tempModuloAxisMaster.Enable := #AxisMaster.Modulo.Enable;
#tempModuloAxisMaster.StartValue := #AxisMaster.Modulo.StartValue;
#tempModuloAxisMaster.Length := #AxisMaster.Modulo.Length;
Checking the read and write index from the DB "ProductPositionTable” of the joint
data management. If read and write index differ, the function is enabled, the cam
disc is interpolated and if no synchronism is currently active, cam disc
synchronization can be started as follows:
4. First of all the read index is determined and the position saved is read from the
table.
5. Starting from the product position, the position of the processing unit
(#PRODUCTBELT_SYNC_POSITION) and the synchronization length
(#PRODUCTBELT_SYNC_DISTANCE), which are included in the constants,
the parameters of the "MC_CamIn” technology function are determined for the
synchronization.
6. If required, the "statMasterOffset” parameter may have to be corrected again,
whilst taken the modulo settings of the master axis into account.
7. The synchronous operation is then started via the "statExecute” tag and the
output signals of the function block are set accordingly.
//+++ Control machine function +++
//Check product position table
IF ((#ProductPositionTable.ReadIndex_SynchronousOperation <>
#ProductPositionTable.WriteIndex_MeasuringInput)
AND (#FunctionEnable = True)
AND (#statCamIsInterpolated = True)
AND (#statExecute = False))
THEN
//Get actual read index
#tempReadIndex :=
#ProductPositionTable.ReadIndex_SynchronousOperation;
//Read saved product position
#statSavedProductPosition :=
#ProductPositionTable.PositionTable[#tempReadIndex];
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